[#126] Add mount integration

[bn-darindouglass-zz]

• Add new formatting-stack.mount namespace for configuring on-up
  hooks
• Add mount tests and example repl/dev implementation

Brief

#126

QA plan

Green tests

Author checklist

• I have QAed the functionality
• The PR has a reasonably reviewable size and a meaningful commit history
• I have run the branch formatter and observed no new/significative warnings
• The build passes
• I have self-reviewed the PR prior to assignment
• Additionally, I have code-reviewed iteratively the PR considering the following aspects in isolation:
  • Correctness
  • Robustness (red paths, failure handling etc)
  • Modular design
  • Test coverage
  • Spec coverage
  • Documentation
  • Security
  • Performance
  • Breaking API changes
  • Cross-compatibility (Clojure/ClojureScript)

Reviewer checklist

• I have checked out this branch and reviewed it locally, running it
• I have QAed the functionality
• I have reviewed the PR
• Additionally, I have code-reviewed iteratively the PR considering the following aspects in isolation:
  • Correctness
  • Robustness (red paths, failure handling etc)
  • Modular design
  • Test coverage
  • Spec coverage
  • Documentation
  • Security
  • Performance
  • Breaking API changes
  • Cross-compatibility (Clojure/ClojureScript)

[bn-darindouglass-zz]

I'm not seeing a build spin up, so I haven't checked that box. However, tests do pass locally.

[vemv]

I'm not seeing a build spin up, so I haven't checked that box. However, tests do pass locally.

👍! I appreciate the care being placed.

Sometime soon I'll merge this directly (to a branch other than master), so that I can apply suggestions directly. That way we can cut a release quickly including your PR.

Thanks for the contribution!

[bn-darindouglass-zz]

My pleasure! I use mount basically exclusively and didn't want to go about hacking mount + formatting-stack locally. :)

[vemv]

It would help me to understand - can (mount/start) perform code-loading (like a clojure.core/require or a tools.namespace.repl/refresh)?

If that were the case, this test would be unlike its Component and Integrant cousins

[bn-darindouglass-zz]

mount/start isn't really smart in-and-of-itself, it really just calls :start on all the defstates that it knows about.

However, mount automatically handles re-compilation (basically just (mount/stop) (mount/start)) of its defstates whenever a namespace is recompiled.

So if someone ran (require ... :reload) or ran C-c C-k in a CIDER repl on a namespace with a defstate, all hooks would be called.

[vemv]

Merging against nedap:126--mount where I'll apply feedback directly